The present invention relates to a new drug containing the same as an effective component for treating osteopathy.
It is well known that there are a number of physiological active substances in a human body, and that such substances are closely involved in the support of normal biological activities in a human body. Both of such physiological active substances of a human body and synthesized physiological active substances are showing possibilities of being new drugs as well as providing new insights into the development of new drugs. Therefore, the search for such physiological active substances is of utmost importance.
On the other hand, for the treatment of osteopathy such as osteoporosis, calcitonin, female hormone, and activated vitamin D3 and the like are currently used, the remedial effects thereof are not necessarily of satisfactory one.
The object of the present invention is to provide a new substance which is useful as a drug for the remedy of osteopathy.
The present inventors found, while conducting various experiments to search for a substance which promotes the activities of osteoblasts, a new peptide having foregoing effects on osteoblasts which is involved in the bone formation, and the present invention was made through such a finding.
In other words, the present invention provides a peptide and a derivative thereof, said peptide having an amino acid sequence designated by the sequence number 1 shown in the sequence table attached herewith, wherein both of said peptide and said derivative thereof having growth promotion effects and activity promotion effects on osteoblasts. In another aspect of the present invention, it provides a drug having said peptide of the present invention as an effective component for treating osteopathy.
The present invention is further explained in detail hereunder.
The peptide of the present invention has basically an amino acid sequence designated by sequence number 1 shown in the sequence table attached herewith.
Furthermore, with the scope of the present invention, in addition to said peptide having an amino acid sequence designated by the sequence number 1 shown in the sequence table attached herewith, a derivative of said peptide is included, wherein said derivative having growth promotion effects and activity promotion effects on osteoblasts. For example, any xe2x80x9cderivative peptidexe2x80x9d referred to in the present invention may include any derivative of said peptide obtained by any chemical modification thereof which may not impede any of said effects. For example, it is well known that by replacing the carboxyl radical at the C end of a peptide with an amino radical, the stability thereof in a human body is increased, and any of such chemically modified peptide is included in the scope of the present invention.
Still further, it is well known to anyone skilled in the art that, in case of a peptide which generally has physiological activity, even when some of the amino acids thereof are replaced by other amino acids, when some amino acids are added thereto, or when some of the amino acids are deleted therefrom, there are cases where the physiological activity is maintained. Therefore, in case of the scope of the present invention, the xe2x80x9cderivative peptidexe2x80x9d includes any peptide wherein some of the amino acids which form said peptide having an amino acid sequence designated by the sequence number 1 are replaced by some other amino acids, wherein some amino acids are added thereto, or wherein there are some amino acids deleted therefrom, and furthermore, among such derivative peptides, any peptide having growth promotion effects and activity promotion effects on osteoblasts are included in the scope of the present invention. For example, the scope of the present invention includes a peptide where not more than 5 amino acids are added, replaced or deleted, or a peptide wherein the degree of homology of the amino acid sequence is not less than 70% and said peptide having growth promotion effects and activity promotion effects on osteoblasts. Furthermore, whether a derivative of a peptide has growth promotion effects and activity promotion effects on osteoblasts may be examined by the method of Examples 2 and 4 described hereunder.
The peptide of the present invention designated by the sequence number 1 has a rather small number of amino acid components, with such number being 16, it may be easily synthesized by a chemical synthesizing method of any known method. For example, it may be easily produced by using a commercially available peptide synthesizing machine. It may also be easily produced by any of known generic engineering methods, wherein a DNA encoding said amino acid sequence is synthesized by using a DNA synthesizing machine, followed by inserting said DNA into the cloning portion of a commercially available cloning vector thereby transforming the host microorganism, followed further by culturing the same.
As has been experimentally confirmed in the examples described hereunder, the peptide of the present invention has growth promotion effects and activity promotion effects on osteoblasts. Therefore, the peptide of the present invention is useful as a drug for the treatment of osteopathy such as osteoporosis. Osteopathy which can be cured by the peptide of the present invention may be found, for example, in osteomalacia and the like other than osteoporosis.
Because the molecular weight of the peptide of the present invention is relatively low, it may be intravenously administered, hypodermically adminis- tered, intramuscularly administered, as well as orally administered or percutaneously administered after the dosage is prepared by any of the known method.
Although the amount of dosage may be appropriately decided depending on the patient""s condition, it may be generally in the order of 0.1 to 10 mg of the peptide of the present invention per an adult per each day.
Furthermore, in case of intravenous administration, hypodermic administration or intramuscular administration, the peptide of the present invention is preferably administered after dissolving the same into a weak acid buffer solution such as a citric buffer solution (pH 4xcx9c6) or acetic buffer solution (pH 4xcx9c6). In such a case, the concentration of the peptide in the buffer solution is generally in the order of 0. 1 mg/ml xcx9c10 mg/ml. In case of oral administration or percutaneous administration, the peptide is preferably dissolved into a fat-soluble substance (for example, petrolatum and the like) to facilitate the increase of absorption characteristics. In such a case, the concentration of the peptide of the present invention is generally in the order of from 0.1 mg/ml to 100 mg/ml.